U.S. patent number 6,508,969 [Application Number 09/636,244] was granted by the patent office on 2003-01-21 for injection-molded end stop for a slider-operated fastener.
This patent grant is currently assigned to Pactiv Corporation. Invention is credited to Joseph W. Eye, William F. Klepser, Jr., Nathan A. Kolovich, Russell J. Talbo.
United States Patent |
6,508,969 |
Kolovich , et al. |
January 21, 2003 |
Injection-molded end stop for a slider-operated fastener
Abstract
A fastener arrangement includes a fastener, a slider, and an
injection-molded end stop. The fastener includes first and second
tracks. The first track includes a first profile, and the second
track includes a second profile for interlocking with the first
profile. The fastener extends between first and second ends. The
slider is slidably mounted to the fastener for movement between the
first and second ends. The injection-molded end stop is located at
least one of the first and second ends. The end stop terminates the
movement of the slider at the one of the first and second ends. The
end stop includes interior plastic material disposed in an interior
of the fastener between the first and second profiles. The one of
the first and second ends includes a cut edge at an angle relative
to an axis of the fastener extending between the first and second
ends. The end stop may include exterior plastic material along an
exterior of the fastener outside the first and second profiles and
covering the cut edge. A method of forming the end stop is also
disclosed.
Inventors: |
Kolovich; Nathan A. (Rochester,
NY), Talbo; Russell J. (Lyons, NY), Eye; Joseph W.
(Orchard Park, NY), Klepser, Jr.; William F. (Snyder,
NY) |
Assignee: |
Pactiv Corporation (Lake
Forest, IL)
|
Family
ID: |
24551060 |
Appl.
No.: |
09/636,244 |
Filed: |
August 10, 2000 |
Current U.S.
Class: |
264/252;
24/30.5R; 264/263; 264/273; 264/274; 264/275 |
Current CPC
Class: |
B29C
45/14336 (20130101); B65D 33/2591 (20130101); Y10T
24/2598 (20150115); Y10T 24/2532 (20150115); Y10T
24/15 (20150115); Y10T 24/2593 (20150115); Y10T
24/45168 (20150115); Y10T 24/2511 (20150115) |
Current International
Class: |
B29C
45/14 (20060101); B65D 33/25 (20060101); B29C
045/14 (); B29C 070/76 (); B29C 070/78 () |
Field of
Search: |
;264/250,251,252,263,271.1,274,275,267,273,259,277 ;425/814
;24/399,400,3.5R,427,435,436,389 ;383/63,65 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 939 034 |
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Sep 1999 |
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EP |
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0 978 450 |
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Feb 2000 |
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EP |
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1 026 077 |
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Aug 2000 |
|
EP |
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2 085 519 |
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Apr 1982 |
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GB |
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99/24325 |
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May 1999 |
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WO |
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Primary Examiner: Ortiz; Angela
Attorney, Agent or Firm: Jenkens & Gilchrist
Parent Case Text
REFERENCE TO RELATED APPLICATIONS
The present application is being filed concurrently with U.S.
patent application Ser. No. 09/636,421 entitled "Slider-Operated
Fastener With Spaced Notches and Associated Preseals," U.S. patent
application Ser. No. 09/637,037 entitled "Method of Applying a
Slider to a Fastener Carrying Plastic Web," U.S. patent application
Ser. No. 09/635,451 entitled "Method and Apparatus for Guiding a
Fastener in a Bag Making Machine," and U.S. patent application Ser.
No. 09/637,038 entitled "Method and Apparatus for Making Reclosable
Plastic Bags Using a Pre-Applied Slider-Operated Fastener," all of
which are incorporated herein by reference in their entireties.
Claims
What is claimed is:
1. A method of forming an end stop for a fastener arrangement, said
fastener arrangement including a fastener and a slider, said
fastener including first and second tracks, said first track
including a first profile, said second track including a second
profile for interlocking with said first profile, said fastener
extending between first and second ends, said slider being slidably
mounted to said fastener for movement between said first and second
ends, said method comprising: supplying a predetermined amount of
flowable plastic material; guiding said flowable plastic material
to said first end such that a portion of said plastic material
flows along an interior of said fastener between said first and
second profiles for a length "L" adjacent to said first end without
any portion of said plastic material flowing on an exterior of said
fastener along said length "L"; and solidifying said flowable
plastic material.
2. The method of claim 1, wherein said step of supplying said
predetermined amount of flowable plastic material includes passing
said flowable plastic material through a supply line.
3. The method of claim 1, wherein said step of guiding said
flowable plastic material includes injecting said flowable plastic
material between said first end and a mold structure adjacent to
said first end.
4. The method of claim 3, wherein said step of injecting said
flowable plastic material forces said portion of said plastic
material to flow along said interior of said fastener between said
first and second profiles.
5. The method of claim 3, wherein said mold structure includes a
pair of reciprocating molds that close around said first end.
6. The method of claim 3, wherein said mold structure includes an
inner surface forming a receiving channel receiving said flowable
plastic material and a guiding channel guiding said received
plastic material to said first end, said guiding channel being
coupled to said receiving channel.
7. The method of claim 3, wherein said mold structure is chilled,
and wherein said step of solidifying said flowable plastic material
includes chilling said flowable plastic material with said chilled
mold structure.
8. The method of claim 1, wherein said first end includes a cut
edge at an angle relative to an axis of said fastener extending
between said first and second ends, wherein said step of guiding
said flowable plastic material is performed such that said second
portion of said plastic material covers said cut edge.
9. The method of claim 1, wherein said step of guiding said
flowable plastic material includes injecting said flowable plastic
material into said interior of said fastener via an aperture
proximate said first end.
10. A method of forming an end stop for a fastener arrangement,
said fastener arrangement including a fastener and a slider, said
fastener including first and second tracks, said first track
including a first profile and a first downwardly extending portion
below said first profile, said second track including a second
profile for interlocking with said first profile and a second
downwardly extending portion below said second profile, said first
and second downwardly extending portions being attached at their
terminal ends, said fastener extending between first and second
ends, said slider being slidably mounted to said fastener for
movement between said first and second ends, said method
comprising: moving said first and second tracks into a mold while
said terminal ends of said first and second downwardly extending
portions remain attached; and injecting and molding a predetermined
amount of flowable plastic material proximate at least one of said
first and second ends such that at least a portion of said plastic
material flows along an interior of said fastener between said
first and second profiles.
11. A method of forming an end stop for a fastener arrangement,
said fastener arrangement including a fastener and a slider, said
fastener including first and second tracks, said first track
including a first profile, said second track including a second
profile for interlocking with said first profile, said fastener
extending between first and second ends, said slider being slidably
mounted to said fastener for movement between said first and second
ends, said first end including a cut edge at an angle relative to
an axis of said fastener extending between said first and second
ends, said method comprising: injecting and molding a predetermined
amount of flowable plastic material proximate said first end such
that a first portion of said plastic material flows along an
exterior of said fastener outside said first and second profiles at
said cut edge and covers said cut edge while a second portion of
said plastic material extends for a length "L" between said first
and second profiles on an interior surface of said fastener, said
exterior of said fastener along said length "L" being free of said
flowable plastic material.
12. A method of forming an end stop for a fastener arrangement,
said fastener arrangement including a fastener and a slider, said
fastener including first and second tracks, said first track
including a first profile, said second track including a second
profile for interlocking with said first profile, said fastener
extending between first and second ends, said slider being slidably
mounted to said fastener for movement between said first and second
ends, said method comprising: providing a mold structure including
a pair of reciprocating molds; closing said molds about at least
one of said first and second ends such that interior surfaces of
said molds snugly fit against an exterior of said first and second
profiles along a continuous length "L" measured from said first
end; injecting a predetermined amount of flowable plastic material
into a receiving channel formed by said closed molds; guiding said
injected plastic material through a guiding channel formed by said
closed molds such that at least a portion of said plastic material
flows along an interior of said fastener between said first and
second profiles and the flow of said plastic material onto said
exterior of said first and second profiles along said continuous
length "L" is inhibited due to said molds fitting snugly against
said exterior of said first and second profiles, said guiding
channel being coupled to said receiving channel; and opening said
molds.
13. A method of forming an end stop for a fastener arrangement,
said fastener arrangement including a fastener and a slider, said
fastener including first and second tracks, said first track
including a first profile and a first downwardly extending portion
below said first profile, said second track including a second
profile for interlocking with said first profile and a second
downwardly extending portion below said second profile, said first
and second downwardly extending portions being attached to each
other at their terminal ends, said fastener extending between first
and second ends, said slider being slidably mounted to said
fastener for movement between said first and second ends, at least
one of said first and second ends including a cut edge at an angle
relative to an axis of said fastener extending between said first
and second ends, said method comprising: providing a mold structure
including a pair of reciprocating molds; closing said molds about
said one of said first and second ends while said terminal ends of
said first and second downwardly extending portions remain
attached; injecting a predetermined amount of flowable plastic
material into a receiving channel formed by said closed molds;
guiding said injected plastic material through a guiding channel
formed by said closed molds such that at least a portion of said
plastic material flows along an exterior of said fastener outside
said first and second profiles and covers said cut edge, said
guiding channel being coupled to said receiving channel; and
opening said molds.
14. The method of claim 3, wherein said mold structure has a guide
channel that snugly fits around said fastener to inhibit flow of
said plastic material to said exterior of said fastener.
15. The method of claim 1, wherein another portion of said plastic
material flows around an exterior of said fastener at said first
end.
16. The method of claim 1, wherein terminal ends of said track
opposite said profiles are attached.
17. The method of claim 10, wherein said injecting and molding
includes closing a mold around said fastener, said mold has a guide
channel that snugly fits around said fastener to inhibit flow of
said plastic material to said-exterior of said fastener along a
length "L" adjacent to said at least one of said first and second
ends.
18. The method of claim 11, wherein terminal ends of said tracks
opposite said profiles, are attached to each other.
19. The method of claim 12, wherein terminal ends of said tracks
-opposite said profiles are attached to each other.
20. The method of claim 13, wherein said mold has a guide channel
that snugly fits around said fastener to inhibit flow of said
plastic material to said exterior of said fastener along a length
"L" adjacent to said at least one of said first and second ends.
Description
FIELD OF THE INVENTION
The present invention generally relates to reclosable plastic bags
and, more particularly, to an injection-molded end stop for a
slider-operated fastener.
BACKGROUND OF THE INVENTION
A fastener arrangement for reclosable plastic bags typically
includes a fastener, a slider, and a pair of end stops. The
fastener includes first and second tracks. The first track includes
a first profile, and the second track includes a second profile for
interlocking with the first profile. The slider is slidably mounted
to the fastener for movement between opposite ends of the fastener.
The end stops are located at the opposite ends of the fastener.
The end stops perform three functions: (1) preventing the slider
from going past the ends of the fastener, (2) holding the profiles
together to resist stresses applied to the profiles during normal
use of the plastic bag, and (3) minimizing leakage from inside the
plastic bag out through the fastener ends. In U.S. Pat. No.
5,067,208, each end stop is in the form of a fairly rigid
strap/clip that wraps over the top of the fastener. One end of the
strap is provided with a rivet-like member that penetrates through
the fastener fins and into a cooperating opening at the other end
of the strap. Other types of end stops are disclosed in U.S. Pat.
Nos. 5,924,173, 5,833,791, 5,482,375, 5,448,807, 5,442,837,
5,405,478, 5,161,286, 5,131,121, and 5,088,971.
For example, U.S. Pat. No. 5,833,791 proposes an injection-molded
end stop disposed along only an exterior of a fastener outside a
pair of interlocked profiles. The narrow end stop is spaced from a
cut edge at the end of the fastener and extends along the length of
the fastener for only a very short distance. On the one hand, the
manufacturing process of injecting softened plastic material about
the fastener and molding the plastic material into the end stop is
quick, efficient, and cost effective. On the other hand, because
the end stop is so limited in size and is not firmly anchored, the
end stop is weaker than some other types of end stops such as the
above-noted riveted strap. As a result, the end stop might not be
able to withstand some of the abuses and stresses that can be
inflicted by the slider during normal use of the plastic bag.
A need therefore exists for an injection-molded end stop that
overcomes shortcomings associated with prior injection-molded end
stops.
SUMMARY OF THE INVENTION
A fastener arrangement includes a fastener, a slider, and an
injection-molded end stop. The fastener includes first and second
tracks. The first track includes a first profile, and the second
track includes a second profile for interlocking with the first
profile. The fastener extends between first and second ends. The
slider is slidably mounted to the fastener for movement between the
first and second ends. The injection-molded end stop is located at
least one of the first and second ends. The end stop terminates the
movement of the slider at the one of the first and second ends. The
end stop includes interior plastic material disposed in an interior
of the fastener between the first and second profiles. The one of
the first and second ends includes a cut edge at an angle relative
to an axis of the fastener extending between the first and second
ends. The end stop may include exterior plastic material along an
exterior of the fastener outside the first and second profiles and
covering the cut edge. A method of forming the end stop is also
disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent
upon reading the following detailed description and upon reference
to the drawings in which:
FIG. 1 is an isometric view of a reclosable plastic bag embodying
the present invention, the bag including a fastener arrangement
along its mouth, the fastener arrangement including a
slider-carrying fastener and a pair of end stops at opposite ends
of the fastener;
FIG. 2 is an enlarged isometric view of one end of the fastener
prior to forming an end stop;
FIG. 3 is an enlarged isometric view of the end of the fastener
showing a pair of reciprocating molds in an open position;
FIG. 4 is a side view of one of the molds;
FIG. 5 is an enlarged isometric view of the end of the fastener
showing the pair of molds in a closed position while forming the
end stop;
FIG. 6 is an enlarged isometric view of the end of the fastener
showing the pair of molds returned to the open position after
forming the end stop;
FIG. 7 is an enlarged isometric view of the end of the fastener
after forming the end stop;
FIG. 8 is a section view taken generally along line 8--8 in FIG.
7;
FIG. 9 is a section view taken generally along line 9--9 in FIG.
7;
FIG. 10 is a side view of the end of the fastener prior to forming
an end stop, in accordance with an alternative embodiment of the
present invention;
FIG. 11 is a section view taken generally along line 11--11 in FIG.
10; and
FIG. 12 is a section view similar to FIG. 11 after forming the end
stop.
While the invention is susceptible to various modifications and
alternative forms, a specific embodiment thereof has been shown by
way of example in the drawings and will herein be described in
detail. It should be understood, however, that it is not intended
to limit the invention to the particular forms disclosed, but on
the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention as defined by the appended claims.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
Turning to the drawings, FIG. 1 depicts a reclosable plastic bag 10
embodying the present invention. The bag 10 includes a pair of
opposing panels 12 and 14 joined along a pair of sides 16 and a
bottom 18 bridging the pair of sides. The bag 10 also includes a
fastener arrangement 19 along its mouth opposite the bottom 18. The
fastener arrangement 19 includes a fastener 20, a slider 22, and a
pair of injection molded end stops 24. Referring to FIG. 2, the
fastener 20 includes first and second opposing tracks 26 and 28.
The first track 26 includes a first profile 30, and the second
track 28 includes a second profile 32 for interlocking with the
first profile. The first profile 30 preferably forms a groove, and
the second profile 32 preferably forms a rib for insertion into the
groove of the first profile. Referring back to FIG. 1, the
injection-molded end stops 24 are located at opposite ends of the
fastener 20. The slider 22 is slidably mounted to the fastener 20
for movement between these opposite ends. The end stops 24
terminate the movement of the slider 22 at the respective opposite
ends of the fastener 20. In one embodiment, the slider 22
disengages the profiles 30 and 32 as the slider 22 is moved in an
"opening" direction toward one of the end stops 24, and engages the
profiles 30 and 32 as the slider 22 is moved in a "closing"
direction toward the other of the end stops 24.
FIG. 2 is an enlarged view of one end of the fastener 20 prior to
forming the end stop 24. The end of the fastener 20 includes a cut
edge 34 at an angle relative to an axis of the fastener 20
extending between the fastener's opposite ends. This angle is
preferably 90 degrees such that the cut edge 34 is perpendicular to
the axis of the fastener 20.
FIGS. 3 through 6 depict an end stop forming station for applying
each end stop 24 to the fastener 20. Each plastic end stop 24 is
made from a predetermined amount of flowable plastic material that
migrates from or is injected from a supply tube 36 through one of a
pair of chilled, reciprocating molds 38 and 40. In the illustrated
embodiment, the supply tube 36 delivers the plastic material to the
inner surface or cavity of the mold 38.
The end stop 24 is composed of one or more flowable materials
capable of being solidified and anchored to the fastener 20. The
flowable materials may be thermoplastic or thermoset materials.
Typical base materials for making the end stop may include
polyolefins such as polymethylpentene, cyclic olefin copolymer and
blends of these polymers with PE or PP; thermoplastics such as
ethylene-vinyl acetate, polyethylene, polyvinyl acetates,
polypropylene, polyesters (PET, PPT, PBT, PEN, etc.), polyamides
(nylon6, nylon 6,6, etc.), polycarbonate, polyarylates,
polysulfones (PSU, PESU, etc.), polyimides (PEI, PAI, etc.), liquid
crystal polymers, acrylics (PMMA, etc.), styrenics (PS, HIPS),
polyphenylene oxide/sulfide (PPO/PPS), polyacetals, polyvinyl
butyrate, cellulosics (cellulose acetate, triacetate, etc.),
polyketones (peek, ETC.), polyurethanes, fluorohydrocarbones (PTFE,
ECTFE, PVDF, etc.) and others; and thermosets such as phenolic
resins, amino resins, unsaturated polyester resins, epoxy resins,
urethanes, silicone resins, allyl resins, etc. Additional modifying
components may include some of the following or combinations of the
following: 1) tackifiers to promote wetting, flexibility, and
adhesion, such as rosin, tacky polymers, terpenes, hydrocarbons,
and chlorinated hydrocarbons, 2) plasticizer to promote flexibility
and wetting, such as phthalates, glycolates, polybutenes, and
mineral oil, 3) wax to dilute, nonblock, rigidify and promote
wetting and vary setting speed, such as paraffin, microcrystalline,
vegetable and synthetic wax, 4) extender to lower cost and control
flow in melt or color, such as talc, barytes, or clay, 5)
antioxidant to maintain and stabilize viscosity, color, and odor,
such as hindered phenols, and 6) colorants.
The inner surface of each mold (e.g., mold 38 in FIG. 4) defines a
funnel shaped receiving channel 42 receiving the flowable plastic
material from the supply tube and a guiding channel 44 guiding the
received plastic material to the end of the fastener 20. The
guiding channel 44 includes a deep section 44a and a shallow
section 44b. The deep section 44a is directly coupled to a lower
end of the receiving channel 42 and holds the fastener's cut edge
34 and immediately adjacent section when the molds 38 and 40 are
closed around the end of the fastener 20. The deep section 44a is
sufficiently deep that a small gap exists between the outer surface
of the associated fastener profile and the wall of the deep section
44a when the molds 38 and 40 are closed around the end of the
fastener 20. The shallow section 44b extends from the deep section
44a and holds a fastener portion proximate the cut edge 34 when the
molds 38 and 40 are closed around the end of the fastener 20 (see
FIG. 5). The shallow section 44b is shaped to fit snugly around the
outer surface of the associated fastener profile when the molds 38
and 40 are closed around the end of the fastener 20.
At the end stop forming station, the reciprocating molds 38 and 40
are initially in an open position depicted in FIG. 3. In response
to conveying the end of the fastener 20 between the separated molds
38 and 40, the molds 38 and 40 are moved to a closed position
depicted in FIG. 5. While the molds 38 and 40 are closed around the
end of the fastener 20, a predetermined amount of flowable plastic
material is forced around and between the fastener profiles by a
conventional back pressure device (not shown) coupled to the supply
tube.
Because of the small gap between the wall of the deep section 44a
of the guiding channel 44 and the associated fastener profile, the
deep section 44a allows a portion of the injected plastic material
to flow along an exterior of the fastener 20 outside the profiles
30 and 32. The exterior plastic material essentially forms a thin
skin covering the outer surface of the fastener profiles 30 and 32
at the end of the fastener 20. Because no gap exists between the
wall of the shallow section 44b of the guiding channel 44 and the
associated fastener profile, the exterior plastic material stops
migrating along the exterior of the fastener 20 at the juncture
between the deep and shallow sections 44a, 44b of the guiding
channel 44. In addition to flowing along an exterior of the
fastener 20, the injected plastic material covers the cover edge
34. As the plastic material covers the cut edge 34, a portion of
the injected plastic material enters an interior of the fastener 20
via the cut edge 34 and flows inwardly between the profiles 30 and
32, starting from the cut edge 34. The chilled molds 38 and 40
shape and solidify the plastic material.
After the injected plastic material is molded around and between
the profiles 30 and 32 and solidified, the reciprocating molds 38
and 40 are returned to the open position depicted in FIG. 6. The
resulting fastener arrangement 19, including the injection-molded
end stop 24, is shown in FIG. 7. As noted above, the plastic
material includes both an exterior portion and an interior portion.
The exterior plastic material covers the orthogonal cut edge 34 at
the extreme end of the fastener 20 and, starting from this cut edge
34, the exterior plastic material extends along the exterior of the
fastener 20 for a length L.sub.ext equal to or greater than zero
and, more preferably, at least 0.030 inch, and, most preferably,
about 0.050 to 0.062 inch (see FIG. 9). In addition, the exterior
plastic material has a thickness equal to or greater than zero and,
most preferably, about 0.010 inch. In other words, the thickness
represents the distance by which the exterior plastic material
extends outwardly from the outer surface of the fastener 20. The
interior plastic material extends along the interior of the
fastener 20 for a length L.sub.int of at least about 0.015 inch,
starting from the cut edge 34 (see FIG. 9).
Referring back to FIGS. 1 and 2, the slider 22 includes a separator
finger 23 extending downward from the slider's top wall and between
the profiles 30 and 32. As indicated by its name, the separator
finger 23 helps to separate or disengage the profiles 30 and 32 as
the slider 22 is moved along the fastener 20 in the "opening"
direction. As the slider 22 is moved along the fastener 20 in
either the "opening" or "closing" direction and approaches an end
of the fastener 20, the separator finger 23 contacts the interior
plastic material of the end stop 24 to terminate the movement of
the slider 22. To aid in terminating the movement of the slider 22,
the end stop 24 and/or the slider 22 may be designed so that the
leading end of the slider simultaneously contacts the exterior
plastic material of the end stop 24. Further information concerning
the slider 22 and the manner in which it operates the fastener 20
may be obtained from U.S. Pat. No. 5,007,143, which is incorporated
herein by reference in its entirety.
In the embodiment of FIGS. 1-9, the injection molding process
causes some plastic material to flow into the interior of the
fastener 20 between the profiles 30 and 32 via the cut edge 34.
This interior plastic material increases the fastener end strength
afforded by the end stop 24. To further increase the end strength,
the fastener 20 may include an aperture 46 proximate each of its
opposite ends as depicted in FIGS. 10 and 11. As shown in FIG. 12,
the aperture 46 allows more plastic material to flow between the
profiles 30 and 32 during the injection molding process.
Specifically, the injection molding process causes plastic material
to flow into the interior of the fastener 20 between the profiles
30 and 32 via both the cut edge 34 and the aperture 46. The
aperture 46 extends from the exterior of the fastener 20 outside
the profiles 30 and 32 to the interior of the fastener 20 between
the profiles 30 and 32. The aperture preferably has a minimum
diameter of about 0.030 inch. At smaller diameters, the aperture
may be created with a puncturing needle; at larger diameters, the
aperture may be created with a punch mechanism.
The end stop is preferably designed to provide a minimum slider
retention force of about 3 to 4.5 pounds, which should retain the
slider on the fastener during normal use of the bag. To achieve
this slider retention force, various parameters may be varied
relative to each other, such as (1) the length L.sub.ext,
thickness, and length L.sub.int, of the end stop, (2) the diameter
of the aperture, and (3) the composition of the end stop. Increases
in one dimension may allow for decreases in another dimension. For
example, it is possible to make a functional end stop by injecting
the plastic material inside the fastener 20 only with no exterior
plastic material.
While the present invention has been described with reference to
one or more particular embodiments, those skilled in the art will
recognize that many changes may be made thereto without departing
from the spirit and scope of the present invention. For example,
the molds can be modified to allow the simultaneous formation of a
pair of injected-molded end stops on adjacent bags in a line of
interconnected bags. In this case, one end stop is formed on a
trailing end of a fastener segment of one bag and another end stop
is formed on a leading end of a fastener segment of the next
adjacent bag. To accomplish the simultaneous formation of a pair of
end stops, each mold can be designed with two sets of identical
channels symmetrical about a vertical plane where each set of
channels is used to receive and guide flowable plastic material for
forming a respective end stop. Each of these embodiments and
obvious variations thereof is contemplated as falling within the
spirit and scope of the claimed invention, which is set forth in
the following claims.
* * * * *